The present invention is directed to isolation and identification of plantproanthocyanidin extracts and particular proanthocyanidin compounds forprevention and treatment of urinary tract infections caused by P-typeEscherichia coli. These extracts can be obtained from any proanthocyanidin-containing plants, including plants of the families Ericaceae, Rosaceae,Pinaceae, Vitaceae and the like. Preferably the extracts are from cranberryplants (especially, Vaccinium macrocarpon) and other plants, particularlyfruit and berry plants from the Vaccinium spp. The extracts and compounds arealso provided as pharmaceutical compositions, food additives and foodcompositions, especially beverages, ground meat preparations and cranberry-containing food products. The invention also relates to methods of reducingpathogenicity of P-type E. coli in the digestive tracts of cattle and reducingP-type E. coli contamination in ground meat as well as methods of detecting P-type bacteria.
